Filtered register architecture to generate actuator signals

ABSTRACT

In various embodiments, apparatus and systems, as well as methods, may include an enhanced register to provide actuator signals to a memory array, the enhanced register including a first memory device including an first enable input, a first data input coupled to a register data input, and first memory device output, the first memory device output to couple to the memory array, and the enhances register to include a second memory device including a second enable input, a second data input coupled to the register data input, and a second memory device output, wherein the second memory device output provides a first output signal indicating when one or more of the actuator signals from the first memory device output are to be coupled to the register data input.

RELATED APPLICATION

This application claims priority under 35 U.S.C. 119 from ItalianApplication No. TO2006A000719, filed Oct. 6, 2006, which application isincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to memory devices, and inparticular the present invention relates to a register architecture usedin conjunction with memory devices.

BACKGROUND OF THE INVENTION

Flash memory devices have developed into a popular source ofnon-volatile memory for a wide range of electronic applications. Flashmemory devices typically use a one-transistor memory cell that allowsfor high memory densities, high reliability, and low power consumption.Common uses for flash memory include portable computers, personaldigital assistants (PDAs), digital cameras, and cellular telephones.Program code, system data such as a basic input/output system (BIOS),and other firmware can typically be stored in flash memory devices.

Flash memory operations such as erase and program are accomplished usingcomplex algorithms composed of many different steps and requiringcontrol over timing, counter, and analog voltages. For example, aprogram operation is typically a loop of program pulses and programverifies executed so that the desired value is written and verified withan appropriate voltage margin. The control of the memory portion of aflash memory, referred to as the memory array, is accomplished bycontrolling one or more actuator signals coupled to the memory array.

A circuit typically referred to as an algorithm controller is designedto manage the execution of the various complex steps of memoryoperations, including controlling the one or more actuator signals. Thealgorithm controller must track the steps of the operation even when oneoperation is suspended in order to service a higher priority operation.The algorithm controller must properly manage the interrupt and thenresume the original operation at an appropriate point to allow thesuspended operation to be correctly completed.

While the algorithm controller executes algorithms, referred to as “useralgorithms,” it is often necessary or desirable to operate the flashmemory in a different mode, for example a test mode, wherein operationsof the flash memory may be controlled by an external tester. In such amode, referred to as a test mode, one or more setting may be applied toeach of the actuator signals controlling the memory array. However, uponexiting the test mode, the setting provided to any of the one or moreactuator signals will not be retained, as the user algorithms completelyre-writes the setting of the actuator signals based on the useralgorithms executed by the algorithm controller during the subsequentuser mode.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a functional block diagram of an example embodimentof a register architecture;

FIG. 2 illustrates a functional block diagram of an example embodimentof a register architecture;

FIG. 3 illustrates a schematic diagram of one or more devices includedin the exemplary embodiments of a register architecture reported in FIG.2;

FIG. 4A illustrates a timing diagram for one or more example embodimentsof register architectures operating in a first mode;

FIG. 4B illustrates a timing diagram for one or more example embodimentsof register architectures operating in at least a first mode and asecond mode;

FIG. 4C illustrates a timing diagram for one or more example embodimentsof register architectures operating in a second mode subsequent tooperating in a first mode;

FIG. 4D illustrates a timing diagram for one or more example embodimentsof register architectures;

FIG. 5A illustrates a functional block diagram of an example embodimentof an enhanced register architecture including filtered registers;

FIG. 5B illustrates a functional block diagram of an example embodimentof an enhanced register architecture including filtered registers;

FIG. 6 illustrates a schematic diagram of one or more devices includedin the exemplary embodiments of a register architecture reported inFIGS. 5A and 5B;

FIG. 7A illustrates a timing diagram for one or more example embodimentsof register architectures operating in a first mode and including afiltered register architecture;

FIG. 7B illustrates a timing diagram for one or more example embodimentsof register architectures including a filtered register architecture;

FIG. 7C illustrates a timing diagram (based on electrical simulations)for one or more example embodiments of register architectures operatingin a second mode after a subsequent first mode and including a filteredregister architecture;

FIG. 8A is a flow chart illustrating several methods according tovarious embodiments;

FIG. 8B is a flow chart illustrating several methods according tovarious embodiments; and

FIG. 9 illustrates an exemplary system incorporating one or more exampleembodiments register architectures.

DETAILED DESCRIPTION

In the following detailed description of the invention, reference ismade to the accompanying drawings that form a part hereof, and in whichis shown, by way of illustration, specific embodiments in which theinvention may be practiced. In the drawings, like numerals describesubstantially similar components throughout the several views. Theseembodiments are described in sufficient detail to enable those skilledin the art to practice the invention. Other embodiments may be utilizedand structural, logical, and electrical changes may be made withoutdeparting from the scope of the present invention. The followingdetailed description is, therefore, not to be taken in a limiting sense,and the scope of the present invention is defined only by the appendedclaims and equivalents thereof.

One or more embodiments of the present invention include enhancedregisters. Enhanced registers are registers that include a filterregister and filtering, as described in further detail below. Inaddition, one or more embodiments of the present invention includeswitching devices and logic circuitry as part of or associated with thecontrol and operation of the filter register, as described in furtherdetail below.

FIG. 1 illustrates a functional block diagram of an embodiment of aregister architecture 100. Register architecture 100 includes memorydevice 104. In various embodiments, the memory device 104 is coupled toa processor 102 to form part of an electronic system. The memory device104 has been simplified in FIG. 1 to focus on features of the memorythat are helpful in understanding the various embodiments describedherein.

Processor 102 is coupled to memory device 104. Memory device 104includes interface and control block 106, switching block 108, andenhanced registers included in enhanced registers block 110.

Processor 102 is coupled to memory device 104 through address lines 130,data lines 132, and control lines 134. Although address lines 130, datalines 132, and control lines 134 are each shown as a single line, thesesets of lines are not limited to a particular type of connection, andare not limited to a single conductor or a single transmission line. Oneor more of address lines 130, data lines 132, and control lines 134 mayconsist of multiple conductors or multiple transmission lines.

In FIG. 1, address lines 130, data lines 132, and control lines 134 areshown as coupling to the interface and control block 106. However,embodiments are not limited to lines from the processor being connectedonly to the interface and control block 106. In various embodiments, oneor more signals provided on address lines 130, data lines 132, andcontrol lines 134 may be coupled to other blocks in memory device 104,including but not limited to switching block 108. For example, invarious embodiments, data from data lines 132 is coupled to switchingblock 108, as explained in further detail below.

In an embodiment, address lines 130 are used to send addresses fromprocessor 102 to memory device 104. Addresses are not limited to anyparticular type of addresses, and may include address associated witheach of the enhanced registers in enhanced registers block 110. Addresslines 130 may transmit addresses in parallel using a plurality ofaddress lines included in address lines 130. Address lines 130 maytransmit addresses as serial data. Address lines 130 may include anytype of transmission medium suitable for transmitting address data.

In an embodiment, data lines 132 are used to send data from processor102 to memory device 104. Data is not limited to any particular type ofdata. In one embodiment, data includes settings to be stored in the oneor more registers included in enhanced registers block 110. In one orore embodiments, data may include data to be written to memory array120. In one or more embodiments, data may include data read from memoryarray 120. Data may be transmitted between interface and control block106 and memory array 120 along data lines 152.

Control lines 134 provide one or more control signals to interface andcontrol block 106. Control signals provided over control lines 134 arenot limited to any particular type of control signals. In variousembodiments, control signals may be digital signals.

Interface and control block 106 is coupled to switching block 108through connection 140. Connection 140 is not limited to any particulartype of connection. Although connection 140 is shown as a single line,connection 140 may include several conductors, and may include one ormore types of transmission lines. In various embodiments, one or moresignals received from processor 102 and one or more signals generated bythe interface and control block 106 are transmitted to switching block108, as is further described below.

Switching block 108 is coupled to enhanced registers block 110 throughconnection 142. Connection 142 is not limited to any particular type ofconnection. Although connection 142 is shown as a single line,connection 142 may include several conductors and may include one ormore type of transmission lines. In various embodiments, switching block108 may include addresses of registers included in enhanced registersblock 110. In various embodiments, connection 142 may be used totransmit data for setting memory devices 113 and 115 included inenhanced registers block 110, as further explained in more detail below.In various embodiments, one or more memory devices 113 and 115 may beemployed as a filter, as explained in further detail below.

In various embodiments, enhanced registers block 110 includes group xregisters 112 and group y registers 114. Group x registers may includeactuator signals for controlling rows associated with memory array 120.Group y registers may include actuator signals for controlling columnsassociated with memory array 120. Enhanced registers block 110 includesconnection 150 coupling enhanced registers block 110 to switching block108. Connection 150 includes one or more control signals used incontrolling one or more of the switching devices 109 of switching block108.

Enhanced registers block 110 is coupled to memory array 120 throughconnection 144. Connection 144 is not limited to any particular type ofconnection. Although connection 144 is shown as a single line,connection 144 may include several conductors and may include one ormore types of transmission lines. In various embodiments, connection 144includes one or more actuator signals used to control operations ofmemory array 120, for example but not limited to, actuator signals forcontrolling rows and columns associated with memory array 120.

Memory array 120 may include flash memory, synchronous flash memory,NAND architecture flash memory, NOR architecture flash memory, and othertypes of non-volatile memory. While the description is directed to flashmemory, the scope of the invention is not so limited. Other types ofmemory devices may include read only memory, dynamic random accessmemory, static random access memory, EEPROM memory. Additionally, thememory device could be a synchronous memory device such as SGRAM(Synchronous Graphics Random Access Memory), SDRAM (Synchronous DynamicRandom Access Memory), SDRAM II, and DDR SDRAM (Double Data Rate SDRAM),as well as Synchlink or Rambus DRAMs and other emerging memorytechnologies as known in the art.

FIG. 2 illustrates a functional block diagram of a register architecture200. Register architecture 200 does not include a filter associated withenhanced registers block 110. Instead, register architecture 200includes group x registers 230 and group y registers 244, which do notinclude the filter as further described in detail with respect to FIGS.5A, 5B, 6, 7A-7C, 8A, 8B, and 9. Further, register architecture 200 doesnot include one or more additional switching devices and one or moreadditional logic circuits associated with and coupled to the filter, asexplained in further detail below. However, an understanding of theregister architecture 200 is useful in understanding the embodiments ofregister architectures that include the filter and the associated one ormore additional switching devices and additional one or more logiccircuits include in registers architectures that include a filter.

Register architecture 200 as shown in FIG. 2 includes the functionalblocks as illustrated in FIG. 1, including interface and control block106, switching block 108, registers block 110 (but not enhancedregisters), and memory array 120. One or more of the couplingsillustrated in FIG. 2 may be part of one or more of the interconnects asshown in FIG. 1. In various embodiments, register architecture 200includes latch 202, controller (CONTR) 204, logic circuit 206, commanduser interface (CUI) 208, MUX(n) 220, and MUX(n) 222.

In various embodiments, register architecture 200 also includes group xregisters 230. Group x registers 230 is representative of any registerin a group, wherein the group is not limited to a particular group, butis designated by the letter “x” as representative of any group ofregisters associated with the group x registers 230. Group x registers230 is not limited to a particular number of registers. Group xregisters 230 may be one or more registers included in the group ofregisters designated as group x registers. In various embodiments, groupx registers 230 provides actuator signals to memory array 120, includingbut not limited to actuator signals associated with the rows included inmemory array 120.

In an embodiment, register architecture 200 includes group y registers244. Group y registers 244 is representative of any register in a group,wherein the group is not limited to a particular group, but isdesignated by the letter “y” as representative of any group of registersassociated with the group y registers 244. Group y registers 244 is notlimited to a particular number of registers. Group y registers 244 maybe one or more registers included in the group of registers designatedas group y registers. In various embodiments, group y registers 244provides actuator signals to memory array 120, including but not limitedto actuator signals associated with the columns included in memory array120. In embodiments employing group y registers 244, MUX(n) 240 andMUX(n) 242 may also be included in register architecture 200.

For the sake of simplicity, the internal diagram of group y registers244 is not shown, but corresponds to the description as provided forgroup x registers 230. Embodiments of the invention are not limited to aparticular number of total group registers. Although group x registers230 and group y registers 244 are shown in FIG. 2, register architecture200 may included any number of group registers, and may include anynumber of registers within any particular group. The number of registersin any particular group is not limited to a same number of registers inany other group included in register architecture 200.

In various embodiments, register architecture includes memory array 120.Memory array 120 is not limited to any particular type of memory.Register architecture is not limited to a single memory array. Forexample, register architecture 200 may include, for example but notlimited to, a second memory array 246. Register architecture 200 is notlimited to any particular number of memory arrays.

In various embodiments, register architecture may receive one or moreexternal signals, including but not limited to an address latch enable(ALE) signal 250, a write enable (WE) signal 252, a data (DQ(n)) signal254, and a command latch enable (CLE) signal 268. These external signalsare not limited to any particular type of signals, and are not limitedto any particular voltage levels. In various embodiments, these externalsignals are digital signals. In various embodiments, registerarchitecture 200 may also receive a combinational signal including acombination of one or more of the above mentioned external signals, forexample but not limited to combinational signal 264. Combinationalsignal 264 includes the WE signal 252 logically ANDed with the inverse(bar) ALE signal 250 logically ANDed with the inverse (bar) CLE signal268.

In various embodiments, the external signals are provided by a devicenot included in register architecture 200, for example but not limitedto processor 102 of FIG. 1. However, external signals are not limited tobeing provided by any particular type of device. External signals may beprovided by a programmer or a tester or any other source or sourcescapable of providing the external signals.

In register architecture 200, latch 202 receives ALE signal 250 at input202 a, WE signal 252 at input 202 b, and DQ(n) signal 254 at input 202c. In an embodiment, latch 202 provides ext_add(n) signal 256 at output202 d. Ext_add(n) signal 256 is not limited to a particular type ofsignal. In one embodiment, ext_add(n) signal 256 includes dataassociated with an address for one or more registers, including but notlimited to group x registers 230 and group y registers 244.

In register architecture 200, controller 204 is not limited to anyparticular type of controller. In various embodiments, controller 204 isan algorithm controller. In various embodiments, controller 204 isembedded in memory device 104 of FIG. 1. Controller 204 may includestorage 205, wherein storage 205 may include addresses for registersincluding, but not limited to, group x registers 230 and group yregisters 244. Storage 205 may include data. Storage 205 may includeinstructions, including instructions for processing read, write, anderase algorithms related to memory, including but not limited to memoryarray 120 and memory array 246.

Controller 204 provides a signal 258 at output 204 a. Signal 258 is notlimited to any particular type of signal. In one embodiment, signal 258is output signal add_algo(n), and includes address data associated withan address for one or more registers, including but not limited to groupx registers 230 and group y registers 244. In one embodiment, thisaddress data is address data stored in storage 205.

Controller 204 provides signal 260 at output 204 b. Signal 260 is notlimited to any particular type of signal. In one embodiment, signal 260is a dat_algo(n) signal, and includes data that may be written to one ormore registers, including but not limited to group x registers 230 andgroup y registers 244. In an embodiment, the data is data stored instorage 205.

Controller 204 provides signal 262 at output 204 c. Signal 262 is notlimited to any particular type of output signal. In one embodiment,signal 262 is a digital signal. In an embodiment, signal 262 is awr_algo signal used to execute a write operation into one or moreregisters, including but not limited to, group x registers 230 and groupy registers 244.

Logic circuit 206 receives signal 262 at input 206 a. Logic circuit 206receives combinational signal 264 input 206 b. In an embodiment, inputsignal 264 is the combination signal WE*ALE(bar)*CLE(bar) as describedabove. Logic circuit 206 receives signal 270 at input 206 c. Logiccircuit 206 provides signal 266 at output 206 d. In an embodiment,signal 266 is a “write register” wr_reg signal. Signal 266 is notlimited to any particular type of signal. In one embodiment, signal 266is a digital signal.

Logic circuit 206 is not limited to any particular type of logiccircuit. Any logic circuit capable of receiving the above describedsignals and providing the signal 266 may be used for logic circuit 206.In various embodiments, logic circuit 206 includes AND gates 206 e and206 f, inverter 206 g, and NOR gate 206 h, coupled as shown in FIG. 2.

In register architecture 200, CUI 208 receives CLE signal 268 at input208 a, WE signal 252 at input 208 b, and the DQ(n) signal 254 at input208 c. Signal 268 is not limited to any particular type of signal. CUI208 provides signal 270 at output 208 d. Signal 270 is not limited toany particular type of signal. In various embodiments, signal 270 is adigital signal. In various embodiments, signal 270 is a register access(reg_acc) signal. In various embodiments, the status of signal 270indicates a mode of operation for register architecture 200 as describedin further detail below.

In various embodiments, register architecture 200 includes multiplexersMUX(n) 220 and MUX(n) 222. MUX(n) 220 and MUX(n) 222 are not limited toany particular type of multiplexer. MUX(n) 220 receives signal 256 atinput 220 a, and receives signal 258 at input 220 b. MUX(n) 220 receivessignal 270 at input 220 c. MUX(n) 220 provides signal 272 at output 220d. In various embodiments, the status of signal 270 at input 220 cdetermines which of inputs 220 a or 220 b is coupled to output 220 d ofMUX(n) 220. Signal 272 is not limited to any particular type of signal.In an embodiment, signal 272 corresponds to one of either signal 256 orsignal 258, as will be described in greater detail below.

MUX(n) 222 receives signal 254 at input 222 a, and receives signal 260at input 220 b. MUX(n) 222 receives signal 270 at input 222 c. MUX(n)222 provides signal 274 at output 222 d. In various embodiments, thestatus of signal 270 at input 222 c determines which of inputs 222 a or222 b is coupled to output 222 d of MUX(n) 222. Signal 274 is notlimited to any particular type of signal. In an embodiment, signal 274corresponds to one of either signal 254 or signal 260, as will bedescribed in greater detail below.

In various embodiments, register architecture 200 includes multiplexersMUX(n) 240, MUX(n) 242, and group y registers 244. MUX(n) 240 receivessignal 256 at input 240 a, signal 258 and input 240 b, and signal 270 atinput 240 c. MUX(n) 240 provides signal 278 at output 240 d. Signal 278is not limited to any particular type of signal. In various embodiments,the status of signal 270 at input 240 c determines which of inputs 240 aor 240 b is coupled to output 240 d of MUX(n) 240. In variousembodiments, signal 278 corresponds to one of either signal 256 orsignal 258.

MUX(n) 242 receives signal 254 at input 242 a, signal 260 at input 242b, and signal 270 at input 242 c. MUX(n) 242 provides signal 280 atoutput 242 d. Signal 280 is not limited to any particular type ofsignal. In various embodiments, the status of signal 270 at input 242 cdetermines which of inputs 242 a or 242 b is coupled to output 242 d ofMUX(n) 242. In various embodiments, signal 280 corresponds to one ofeither signal 254 or signal 260.

Group x registers 230 receives signal 272 at input 230 a, receivessignal 274 at input 230 b, receives signal 266 at input 230 c andprovides signal 276 at output 230 d. Signal 276 is not limited to anyparticular type of signal. In an embodiment, signal 276 includes one ormore actuators(n) signals for controlling processes related to, forexample but not limited to, memory array 120. Although signal 276 isshown in FIG. 2 as a single line, signal 276 may include one or moresignal lines. The one or more signal lines may be provided by aplurality of memory devices, for example but not limited to memorydevices 236(1) through 236(n). The number of memory devices included ingroup x registers 230 is not limited to any particular number. Invarious embodiments, group x registers 230 includes eight memory devices(represented by the dotted line shown in FIG. 2 between memory device236(1) and 236(n). Each of the memory devices 236(1) through 236(n) mayrepresent a bit in an eight bit register. However, group x registers 230is not limited to an eight bit register. Other embodiments may includesixteen bit, thirty-two bit, and sixty-four bit registers, i.e. 2^(n)registers where n is greater than zero and typically greater than four.

Group x registers 230 includes decoder (DEC) 232, and one or more memorydevices 236(1) through 236(n) as described above. Each of memory devices236(1) through 236(n) is associated with a logic circuit, such as logiccircuit 234 as shown coupled to memory devices 236(1) through 236(n).DEC 232 is coupled to MUX(n) 220, and receives signal 272 at input 232a. DEC 232 provides enable signal 290 at output 232 b. Signal 290 iscoupled to an input 234 a of logic circuit 234.

Signal 266 is coupled to another input of logic circuits 234. Forexample, signal 266 is coupled to input 234 b of logic circuit 234. Invarious embodiments, signal 266 is the wr_reg signal.

Logic circuit 234 provides signal 292 at one output, for example output234 c. Signal 292 is not limited to any particular type of signal. Invarious embodiments, signal 292 is a digital signal. Signal 292 includesthe “enr x” signal that enables associated memory devices 236(1) through236(n) to acquire data at another input of each of the memory devices.For example, memory device 236(1) receives the 1 st component of thedata provided as the dat(n) signal 274 at input 236(1)b of memory device236(1). Each of the additional components of the dat(n) signal 274 arereceived at an input of one of the additional memory devices up to andincluding memory device 236(n). When the “enr x” signals is provided,each of the components present in the dat(n) signal 274 will be latchedinto the one of the memory devices 236(1) through 236(n) to which thedat(n) signal 274 is coupled. Signal 274 is provided by the output 222 dof MUX(n) 222.

In various embodiments, the data input into memory device 236(1) isprovided as the actuator x 1 st component portion of signal 276 atoutput 236(1)c of memory device 236(1). In addition, each of the datacomponents input into the additional memory devices through 236(n) areprovided as the additional actuator x component portions of signal 276at each of the outputs of these additional memory devices up to andincluding 236(n) In various embodiments, signal 276 is the first throughthe nth component of group x actuator signals provided to one or morememory arrays, for example but not limited to, memory array 120 andmemory array 246.

The details of group y registers 244 have not been shown for the sake ofsimplicity. However, the details of group y registers 244 include all ofthe embodiments provided for in describing the group x registers 230. Invarious embodiments, the group y registers 244 provides group y actuatorsignals 282 to one or more memory arrays, for example but not limited tomemory array 120 and memory array 246.

FIG. 3 illustrates a schematic diagram 300 of one or more functionalblocks of register architecture 200. Latch 202 includes logic elements202 g, 202 h, 202 i, and 202 j, and further includes pass gates 202 eand 202 f. Based on the status of ALE signal 250 and WE signal 252,latch 202 will latch the status of all signal lines provided as signal254 DQ(n) into latch 202, and provide the status of all latched signallines at output 202 d, and will continue to provide the latched statusof the signal lines at output 202 d even after the data present onsignal 254 DQ(n) has been removed. DQ(n) is shown in FIG. 3 as datalines DQ<7:0>, representing 8 data lines. However, DQ(n) is not limitedto any particular number of data lines. In various embodiments, DQ(n)may include sixteen, thirty-two, or sixty-four data lines, or anothernumber of lines equal to 2^(n) data lines where n is greater than zero.In various embodiments, the latched signals include an address suppliedfrom an external source, as explained in further detail below.

Latch 202 provides signal 256, to MUX(n) 220. MUX(n) 220 includes passgates 220 e and 220 f. Based on the status of the signal present atinput 220 c, MUX(n) 220 may provide the signal lines included in signal256 from latch 202 at output 220 d, or may provide the signal linesincluded in signal 258 at output 220 d. In various embodiments, signal256 includes an address supplied and latched from an external source,wherein signal 258 includes an address supplied by controller 204, asexplained in more detail below. In various embodiments, MUX(n) 220supplies the inverted signals of the signal lines through logic element220 g at output 220 d(bar).

DEC 232 includes logic elements 232 c, 232 d, 232 e, and 232 f. Invarious embodiments, DEC 232 receives at input 232 a the signal linesprovided by MUX(n) 220 at output 220 d, and provides a decoded output asenable signal 290 at output 232 b. The decoded output is provided asenable signal 290, and is applied to one or more logic circuits, such asbut not limited to, logic circuit 234.

In various embodiments, logic circuit 206 includes logic elements 206 e,206 f, 206 g, 206 h, 206 i, 206 j, 206 k, and 2061. Based on the statusof the signal 262 at input 206 a, the ALE signal 250 and WE signal 252at input 206 b, and signal 270 at input 206 c, logic circuit 206 willprovide signal 266 at output 206 d. Signal 266 is applied to one or morelogic circuits, such as but not limited to logic circuit 234. Logiccircuit 234 provides an output as signal 292, which is coupled to anenable input of a memory device, such as memory device 236.

MUX(n) 222 includes pass gates 222 e and 222 f. Based on the status ofthe signal present at input 222 c, MUX(n) 222 may provide the signallines included in signal 254 at output 222 d, or may provide the signallines included in signal 260 at output 220 d. In various embodiments,signal 254 includes data supplied by an external source, wherein signal260 includes data supplied by controller 204, as explained in moredetail below. Again, DQ(n) is not limited to any particular number ofsignal lines. In various embodiments, signal 270 supplied to input 220 cof MUX(n) 220 and input 222 c of MUX(n) 222 may be inverted throughlogic element 302.

Memory devices 236(1) through 236(n) include logic elements 236 e, 236f, and 236 i, and pass gates 236 g and 236 h. Memory devices 236(1)through 236(n) receive signal 292 at input 236 a, and receive thesignals provided on the signal lines from MUX(n) 222 at input 236 b.Memory devices 236(1) through 236(n) provide signal 276 at output 236 d.In various embodiments, memory devices 236(1) through 236(n) include aplurality of flip-flop circuits, wherein each flip-flop circuit storesone of the components of the data signals 274. Memory devices 236(1)through 236(n) are not limited to any particular type of flip-flopcircuit. In various embodiments, memory devices 236(1) through 236(n)include a plurality of individually settable memory devices, for examplebut not limited to, eight individual memory devices each individuallysettable according to data received at input 236 b on a plurality ofdata input lines. In various embodiments, the status of each of theindividual memory devices included in memory device 236(1) through236(n) is provided at one of outputs 236 c (as shown in FIG. 2) asindividual signal lines included in the plurality of signals included inactuator signal 276.

The operation of a register architecture such as register architecture200 will now be described with reference to FIGS. 2, 3, and 4A-4D. Inoperation, register architecture 200 may operate in one or more modes.Register architecture 200 may operate in a first mode, referred to as“user mode,” and in a second mode, referred to as “test mode.” Invarious embodiments, when register architecture 200 is in user mode,registers in group x registers 230 (and group y registers 244 ifpresent) are written to and controlled by the controller 204, and whenregister architecture 200 is in test mode, group x registers 230 (andgroup y registers 244 if present) are written to and controlled based onthe external signals received by register architecture 200. Theseexternal signals may be provided by a processor, such as the processor102 of FIG. 1. In some embodiments, the external signals are receivedfrom a tester or a programmer (as shown for example in FIG. 9), or someother programming device. In various embodiments, processor 102 may beincluded in the tester or programmer proving the external signals.

Operation of register architecture 200 in user mode is now described byreferring to FIG. 2 and FIG. 4A. CUI 208 is designed to recognize if aparticular code on signal 254, the DQ(n) data, is a user mode command orif it is a test mode entry request. Assuming CUI 208 does not receive atest mode entry request, CUI 208 will set signal 270 (reg_acc) to aparticular setting representative of user mode, for example but notlimited to the setting as shown in FIG. 4A. In one embodiment, signal270 will be set to a level corresponding to a digital “zero.” Whensignal 270 is set to represent user mode, signal 270 will be received atMUX(n) 220, and at MUX(n) 222, and will cause MUX(n) 220 and MUX(n) 222to switch to the inputs received from controller 204. MUX(n) 220 willswitch to input 220 b, and will supply a signal corresponding to signal258 at output 220 d. Therefore, signal 272 (add(n)) will correspond tothe signal 258 provided by controller 204. MUX(n) 222 will switch toinput 222 b, and will supply a signal corresponding to signal 260, thedat_algo(n) signal also provided by controller 204, at output 222 d.

In various embodiments including MUX(n) 240, MUX(n) 242, and group yregisters 244, when signal 270 (reg_acc) is set to user mode, MUX(n) 240and MUX(n) 242 will also switch to receive inputs from controller 204.MUX(n) 240 will switch to input 240 b, and will supply a signalcorresponding to signal 258 at output 240 d. Therefore, signal 278 (addy (n)) will correspond to the signal 258. MUX(n) 242 will switch toinput 242 b, and will supply a signal corresponding to signal 260 atoutput 242 d. Therefore, signal 280 (dat y (n)) will correspond todat_algo(n) supplied from controller 204.

In user mode, controller 204 starts operating and writes sequences ofdata (data=dat_algo(n)) into selected registers. The selected registersto be written to are determined by addresses provided by signal 258(address=add_algo(n)). Proper group x actuator signals 276 or group yactuator signals 282 are generated according to the signals provided bycontroller 204. In various embodiments, these data and addressinstructions are stored in storage 205 of controller 204. Storage 205may also include one or more instructions that control the issuance ofthe data and address signals.

Every register group, for example but not limited to group x registers230 and group y registers 244, has a decoder designed to generate anenable signal (en) when the specific address associated with thatregister is provided. In FIG. 2, group x registers 230 includes decoder232 coupled to receive signal 272 at input 232 a. When the specificaddress is received at decoder 232 which corresponds to group xregisters 230, decoder 232 provides an enable signal at output 232 b.The enable signal is not limited to any particular type of signal. In anembodiment, the enable signal is a digital signal. The enable signal isreceived at input 234 a of logic circuit 234. In an embodiment, logiccircuit 234 is an AND logic circuit, and input 234 a is one input to theAND logic circuit. A second signal 266 is received at input 234 b oflogic circuit 234. In an embodiment, input 234 b is the second input tothe AND logic circuit of logic circuit 234.

Signal 266 is provided at output 206 d of logic circuit 206. In anembodiment, when register architecture 200 is in user mode, controller204 provides signal 262 on output 204 c which produces a signal atoutput 206 d of logic circuit 206. In various embodiments, signal 266 isa strobe signal as shown in FIG. 4A. Signal 266 is not limited to anyparticular type of signal. In one embodiment, signal 266 is a digitalsignal. When the strobe signal provided as signal 266 is “on” or in anenabled state, signal 266 is applied to input 234 b of logic circuit234. When applied along with the enable signal provided from decoder 232at input 234 a of logic circuit 234, logic circuit 234 will generate anenable register x (enr(x)) signal 292 at input 236 a of memory device236. Activation of the enable register x signal at input 236 a willcause the data bits present at inputs 236 b of each memory devices236(1) through 236(n) to be written into group x registers 230. The databits provided at the inputs 236 b of each of memory devices 236(1)through 236(n) are generated by controller 204 at output 204 c as signal260, and are coupled to the inputs 236 b through MUX(n) 222, which isswitched to receive signal 260 from controller 204 and provide acorresponding signal 274 to memory devices 236(1) through 236(n).

The data bits provided by controller 204 and stored into memory devices236(1) through 236(n) are provided as the actuator signals included insignal 276 at output 236 c of memory devices 236(1) through 236(n).Thus, by providing address data at signal 258, register data at signal260, and a strobe signal at signal 262, controller 204 may write, eraseand rewrite data into memory devices 236(1) through 236(n), and thuscontrol actuator signal 276, which in turn controls operationsassociated with one or more memory arrays, such as memory array 120 andmemory array 246.

In a similar manner, in embodiments that include MUX(n) 240, MUX(n) 242,and group y registers 244, when register architecture 200 is operatingin user mode, controller 204 may direct write operations to group yregisters 244 by providing at signal 258 an address that corresponds togroup y registers 244. The components included in group y registers 244are a duplication of those shown for group x registers 230, and havebeen omitted from FIG. 2 for the sake of simplicity. When signal 258includes an address that corresponds to group y registers 244, thedecoder included in the group y registers 244 provides an enable signalto the logic circuit included in the group y registers 244, which, whenalso provided with a wr_reg strobe signal from signal 266, would providean enable register y (enr(y)) signal to the memory devices of group yregisters 244. Controller 204 also provides the data bits as signal 260,coupled through MUX(n) 242 to be provided to the memory devices of groupy registers 244, and written as actuator signal 282 to the one or morememory arrays.

FIG. 4A shows a timing diagram 400 of signals for a write operation inuser mode. During the entire time period, reg_acc signal 270 remainslow, indicating that the register architecture 200 is in user mode.During the time period designated as time surrounding “(a)” in FIG. 4A,controller 204 provides an address as signal 258 (e.g., add_algo(n)) inFIG. 2) that includes an address 401 that corresponds to group xregisters 230. The address is represented as “regx” in FIG. 4A. Sincereg_acc signal 270 is low, this address data will travel along a pathincluding MUX 220 to decoder 232 as described above with respect to FIG.2. Decoder 232 will decode the address signal, and because the address401 corresponds to the group x registers 230, decoder 232 will providean “en” signal as enable signal 290.

During this same time period, controller 204 will provide data 402 onsignal 260 (e.g., dat_algo(n) in FIG. 2). The signal 260 includes databits to be written to group x registers 230. The data is represented as“datx” in FIG. 4A. Since reg_acc signal 270 is low, this data willtravel along a path through MUX 222 and be provided as dat(n) signal 274at inputs 236 b at each of memory devices 236(1) through 236(n).

During this same time period, controller 204 will provide a strobesignal on signal 262 (e.g., wr_algo in FIG. 2). The signal 262 will beapplied to input 206 a of logic circuit 206. Since reg_acc signal 270 islow, this strobe signal will be provided at output 206 d which iscoupled to logic circuit 234 as wr_reg signal 266 as shown in FIG. 4A.With the enable signal 290 present from DEC 232, the strobe at thewr_reg signal 266 will cause logic circuit 234 to provide a signal 292at inputs 236 a of each of memory devices 236(1) through 236(n), causingthe data present at the inputs 236 b of each of memory devices 236(1)through 236(n) to be written into memory devices 236(1) through 236(n).Writing data to memory devices 236(1) through 236(n) will result in theactuator signals 276 for group x registers 230 to now be set accordingto the written data. This is represented by inflection point 403 asshown in FIG. 4A for actuators x signal 276.

A similar process is show in FIG. 4A relating to controller 204 writingdata to group y registers 244 in user mode. During the time periodsurrounding the time designated as “(b)” in FIG. 4A, controller 204provided address 404, shown as “regy” and relating to the address ofgroup y registers 244. During this time period, controller 204 alsoprovides data 405, shown as “daty” and relating to data to be written togroup y registers 244. Because signal 270 is low, these address and datasignals are passed through to the group y registers through MUX(n) 240and MUX(n) 242 respectively in a similar manner as described above forthe group x registers 230. During this time period, controller 204generates the strobe signal 262 (wr_algo). Because signal 270 is low, astrobe signal appears on wr_reg signal 266, causing the enr y signal 407be strobed, as shown in FIG. 4A. Strobing the enr y signal 407 willcause the data from controller 204 to be written to the group yregisters 244 in a similar manner as described above with respect to thegroup x registers 230. Writing the data to the group y registers 244will cause the actuator signals 282 to now be set according to the data405 included in “daty”. This setting of actuator signals 282 isrepresented by inflection point 406 in FIG. 4A.

In this manner, one or more algorithms may be executed by controller 204that cause controller 204 to write and re-write the data to any of groupx registers 230 or group y registers 244. Through these manipulations,controller 204 is able to control operations related to memory array120, and the additional memory array 246 if present.

In addition to the user mode, register architecture 200 of FIG. 2 mayoperate in test mode. In various embodiments, CUI 208 is capable ofdetecting that a test mode is desired based on one or more patterns orlevels of external signals received at CUI 208. Detection of a test modeis not limited to any particular signal or sequence of signals. However,when a determination has been made that a test mode is desired, CUI 208will provide signals at output 208 d that will cause registerarchitecture 200 to operate in test mode. During test mode, the MUXesillustrated in FIG. 2 (220, 222, 240, 242) will be signaled to switch soas to provide addresses, data and control signals supplied from theexternal signal lines to group x registers 230 and group y registers244. While in test mode, the external signals, and not controller 204,may write and re-write data to at least one of group x registers 230 andgroup y registers 244, and thus control the operation of memory array120 (or memory array 246 if present) as is further described in moredetail below.

FIG. 4B illustrates waveforms 430 for register architecture 200. In anembodiment, CUI 208 determines that a test mode is desired by monitoringsignal 268 (CLE), signal 252 (WE), and signal 254 (DQ(n)). Asillustrated in FIG. 4B, around time period “(a)” the CLE signal 268changes from a low to a high state, the WE signal 252 changes from a lowto high state, and the code representing a request to enter registeraccess test mode appears on the DQ(n) signal 254 line. At this time, CUI208 determines that register access test mode is desired and changes thelevel of reg_acc signal 270, from a low state to a high state.

The change in the level of reg_acc signal 270 is received by each of theMUXes 220, 222, 240, and 242. Reg_acc signal 270 is applied to thecontrol portion of MUXes 220, 222, 240, 242 so that the MUXes will shiftand connect the externally supplied address signals and the externallysupplied data signals to group x registers 230 and group y registers244. For example, when the level of reg_acc signals 270 associated withthe test mode is applied to input 220 c of MUX(n) 220, MUX(n) 220 willswitch so that input 220 a is coupled to output 220 d. This switchingwill thereby couple external addresses supplied from latch 202 as shownin FIG. 2 as ext_add(n) signals 256 to decoder 232, as shown in FIG. 2.

In addition, when the level of reg_acc signal 270 associated with theregister access test mode is applied to input 222 c of MUX(n) 222,MUX(n) 222 will switch so that input 222 a is coupled to output 222 d.This switching will thereby couple the external data signal 254 (DQ(n)in FIG. 2) to the data input, for example inputs 236(1)b through 236(n)bof memory device 236(1) through 236(n).

In addition, input signal 264, which is a combination of threeexternally supplied signals (WE*ALE(bar)*CLE(bar)) is provided to logiccircuit 206 at input 206 b. The reg_acc signal 270 is also supplied toinput 206 c of logic circuit 206. Because reg_acc signal 270 isindicating a test mode, logic circuit 206 will couple the signalsprovided by external signal 264 to output 206 d, the wr_reg signal 266.Logic circuit 206 will also disconnect the wr_algo signal 262 providedby controller 204 from the output 206 d.

Thus, by changing the level of reg_acc signal 270 to indicate a testmode, register architecture 200 of FIG. 2 is now arranged to receiveexternal address, external data, and external strobe signals in place ofthe signals provided by controller 204. When these externals signals arecontrolled by a device such as the processor 102 in FIG. 1, or someother tester or programming device, the processor, tester, or otherprogramming device may write and re-write data to group x registers 230and group y registers 244, and thus control memory array 120 (or memoryarray 246 if present).

Referring to FIG. 4B, once the register access test mode has beendetermined, reg_acc signal 270 is in a high state, indicating that theregister architecture is in test mode. At the time period approximatelysurrounding “(b)” in FIG. 4B, address data 420 for group x registers230, represented by “regx” is provided on DQ(n) signal 254 at latch 202in FIG. 2. Latch 202 can be signaled, for example using ALE signal 250and WE signal 252, causing the address data present on DQ(n) signal 254to be latched to output 202 d, This latched address data is provided asext_add(n) 256 as shown in FIG. 2. The ext_add(n) signal 256 is suppliedto decoder 232 through MUX(n) 220 as described above. When the addressdata as shown in FIG. 4B corresponds to the address of group x registers230, the enable signal 290 will change state and provide an enablesignal to logic circuit 234 through signal 290 as shown in FIG. 2.

At the time period surrounding “(c)” of FIG. 4B, data 422 to be writteninto group x registers 230 and represented by “datx” is provided onDQ(n) signal 254. As illustrated in FIG. 2, this data signal is provideddirectly to MUX(n) 222 at input 222 a, and thus is also provided atoutput 222 d, which is coupled to data inputs 236 b of each of memorydevices 236(1) through 236(n).

By strobing the input 206 b of logic circuit 206, at around time “(c)”in FIG. 4B, the wr_reg signal 266 will be strobed, causing the enr xsignal 292 to be strobed. This combination of signals, including theaddress data supplied to the decoder 232 and the data present at inputs236 b, will cause “datx” to be written to memory devices 236(1) through236(n). Writing the data to memory devices 236(1) through 236(n) willcause the actuator signals 276 to now be set according to the datawritten to memory devices 236(1) through 236(n). This is represented byinflection point 408 in FIG. 4B for actuator x signals 276.

The strobe input on input 206 b of logic circuit 206 is provided assignal 266. However, since register architecture 200 is now in testmode, logic circuit 206 in FIG. 2 is now configured to couplecombinational signal 264 to the output 206 d as wr_reg signal 266.Further, logic circuit 206 has disconnected controller 204 from theoutput 206 d, and so controller 204 is no longer affecting the wr_regsignals provided as signal 266.

Additional signals may be used to write data to group y registers 244 asillustrated by the signals surrounding time periods “(d)” and “(e)” inFIG. 4. At the time period surrounding “(d)” address data 424 associatedwith group y registers 244 (“regy”) is provided by DQ(n) signal 254 andlatched as ext_add(n) signal 256. At the time period surrounding “(e)”data 426 is provided by DQ(n) signal 254 and strobed into group yregisters 244 in conjunction with a strobe signal on enr y signal 392,thus setting actuator signals 282 according to the received data. Thisis represented by the inflection point 410 in FIG. 4B.

Termination of the test mode may be detected by a combination of signalsprovided to CUI 208. In one or more embodiments, CUI 208 is capable ofdetecting that a test mode is terminated based on one or more patternsor levels of signals received at CUI 208 from external signals CLE 268,WE signal 252, and DQ(n) signal 254. Detection of the termination of atest mode is not limited to any particular signal or sequence ofsignals. However, when a determination that a test mode is to beterminated has been detected, CUI will return the reg_acc signals 270 toa level that will indicate a test mode is no longer in effect. At thistime, operation of the register architecture 200 may return to one ormore different modes, for example, the user mode as described above.

In test mode, signals provided though external signal lines, for exampleaddress lines 130, data lines 132, and control lines 134, as shown inFIG. 1, may be used to write and re-write data to group x registers andgroup y registers, and thus control the operation of memory array 120(and memory array 246 if present). As described above, test modeincludes switching the MUXes, for example MUXes 220, 222, 240, and 242,to couple their outputs to the inputs coupled to or controlled by theexternal signals. This also has the effect of disconnecting the groupregisters from the address signals and the data signals provided bycontroller 204. As also noted above, logic circuits, for example logiccircuit 206 of FIG. 2, disable controller 204 from strobing the wr_regsignal 266, which controls the time for writing data into the groupregisters. Thus, during test mode, even if controller 204 were operatingto provide signals on its outputs (for example, outputs 204A-C in FIG.2) these signals would be ignored because they would be disconnectedfrom the inputs that are now controlling the group registers.

Because of this separation, test programs can be performed in the testmode without having to perform any modifications to the software,firmware, or hardware associated with the operation of the registerarchitecture in user mode. If different test programs or routines aredesired, the routines or programs may be changed by altering theexternal signals provided in the test mode, without the need to changeanything associated with the operations of the register architecture inuser mode.

However, when returning to user mode, the controller 204 again writesdata to group x registers 230 (and group y registers 244 if present)according to the instructions, addresses, and data included incontroller 204. It is therefore not possible for register architecture200 to maintain the settings written to the group registers in test modeonce the controller 204 again executes one or more of its algorithmsthat include writing data to the group registers. The algorithms ofcontroller 204 re-writes the group register contents according to thealgorithm being performed by controller 204, and thus removes theactuator setting provided during test mode for the particular registerbeing written to in the user mode.

FIG. 4C illustrates waveforms 450 representing this overwriting of theactuator settings provided in a test mode during a subsequent user mode.Around time period “(a)” the combination of CLE signal 268, ALE signal250, and WE signal 252, along with DQ(n) signal 254 indicate that arequest to enter the register access test mode is being made. Inresponse, signal 270 (reg_acc) changes state to indicate that theregister access test mode is active. Time periods “(b),” “(c),” and“(d)” represent addressing a register (for example a register “51” asshown by signal 254 latched as ext_add(n) at inflection point 451),writing data to the register (for example hexadecimal data 02,represented as binary 0000 0010), and then exiting test mode. In variousembodiments, example register 51 is at least one of group x registers230 or group y registers 244. Writing hexadecimal data 02 to register 51sets actuator 51, bit 1 high (wherein register 51 includes for examplebit 0 through bit 7), and sets all the other bits (in particular bit 4)of actuator 51 to low, as shown in FIG. 4C by signals 460 and 462respectively.

In various embodiments, time period “(e)” may represent a mode otherthan user mode or test mode. At time period “(f)”, external signalsrequesting entry of user mode are provided. In various embodiments, usermode may be resumed after exiting test mode without the need for arequest to enter user mode. As noted above, in user mode the groupregisters are being addressed, and data is being written to the groupregisters as it is being provided by controller 204. At time period“(g),” register 51 is again addressed, this time based on an algorithmprovided by controller 204, and an hexadecimal data value of 10, (forexample as represented as a binary 0001 0000), is written to register51. As a result, the status of bit 1 of register 51 is changed(overwritten) to a low state, and the state of bit 4, which was left lowfollowing the test mode, is changed (overwritten) to a high state, asshown by inflection points 470 and 472 respectively.

Thus, register architecture 200 overwrites any particular registersettings provided in test mode once the particular register is writtento in a subsequent user mode.

FIG. 4D illustrates exemplary waveforms 490, obtained from electricalsimulations, present at various points in register architecture 200 overtime. Exemplary waveforms 490 in FIG. 4D include ALE signal 250, WEsignal 252, DQ(n) signal 254, signal 270 (rec_acc), signal 256 (ext_add(n)), signal 258 (add_algo(n)), signal 272 (add(n)), signal 274(dat(n)), signal 260 (dat_algo(n)), signal 290 (en), signal 292 (enr).FIG. 4D also includes signal 276(4) and signal 276(1) (provided asoutputs from exemplary register 51 bits 4 and 1 respectively andcorresponding to signals 460 and 462 of FIG. 4C).

FIG. 5A illustrates a block diagram of register architecture 500.Register architecture 500 includes latch 202, controller 204, logiccircuit 206, MUX(n) 220, MUX(n) 222, decoder 232, logic circuit 234, andmemory devices 236(1) through 236(n) as described above with respect toFIG. 2. In various embodiments, latch 202, controller 204, logic circuit206, MUX(n) 220, MUX(n) 222, decoder 232, logic circuit 234, and memorydevices 236(1) through 236(n) receive and provide one or more of thesame signals as described above with respect to FIG. 2.

In addition, register architecture 500 includes Command User Interface(CUI) 508, logic circuit 509, MUX(n) 524, logic circuit 526, enhancedgroup x registers 530, logic circuit 538, and memory devices 540(1)through 540(n).

In various embodiments, register architecture 500 also includes enhancedgroup y registers 544 and associated multiplexers and memory devices, asshown in FIG. 5B. For the sake of simplicity, the details of thesedevices are similar or the same as described for enhanced group xregisters 530, and so the details in FIG. 5B have been omitted. Theenhanced group y registers 544 are not shown in FIG. 5A for the sake ofsimplicity. However, in various embodiments, enhanced group y registers544 would include all of the features described with respect to enhancedgroup x registers 530. In various embodiments, enhanced group yregisters 544 would be coupled to signal 256, 258, 572, 254, and 260through multiplexers MUX(n) 240, MUX(n) 242, and MUX(n) 546 as shown inFIG. 5B. As also shown in FIG. 5B, enhanced group y registers 544 wouldalso receive signals 266 and 571, and would provide signal 282 (actuatory (n)) and signal 283 (filt y (n)).

Returning to FIG. 5A, latch 202 receives the ALE signal 250, the WEsignal 252, and the DQ(n) signal 254, and provides latched addresssignals at output 202 d as signal 256 to MUX(n) 220. Controller 204 mayprovide addresses as signal 258 (add_algo(n)). Depending on the statusof signal 572 at input 220 c of MUX(n) 220, MUX(n) 220 will provideeither the latched address signals or the address signals fromcontroller 204 to decoder 232.

In register architecture 500, CUI 508 receives CLE signal 268 at input508 a, WE signal 252 at input 508 b, and DQ(n) signal 254 at input 508c. CUI 508 provides signal 270 (reg_acc) at output 508 d. In addition,CUI 508 provides signal 570 (filt_acc) at output 508 e. Signal 570 isnot limited to any particular type of signal. In one embodiment, signal570 is a digital signal. In various embodiments, signal 570 is a filteraccess (filt_acc) signal.

Logic circuit 509 receives signal 570 at input 509 a. Logic circuit 509receives combinational signal 264 at input 509 b. Logic circuit providessignal 571 at output 571 c. Logic circuit 509 is not limited to anyparticular type of logic circuit. In an embodiment, logic circuit 509 isan AND logic circuit, wherein signal 570 and signal 264 are logicallyANDed to provide signal 571. Signal 571 is not limited to any particulartype of signal. In an embodiment, signal 571 is a digital signal. Invarious embodiments, signal 571 is a write filter (wr_filt) signal.

Logic circuit 526 receives signal 270 (reg_acc) at input 526 a, andreceives signal 570 (filt_acc) at input 526 b. Logic circuit 526provides signal 572 at output 526 c. Logic circuit 526 is not limited toany particular type of logic circuit. In an embodiment, logic circuit526 is an OR logic circuit, wherein signal 270 and signal 570 arelogically ORed to provide signal 572. Signal 572 is not limited to anyparticular type of signal. In an embodiment, signal 572 is a digitalsignal. If present, MUX(n) 240 and MUX(n) 242 (as shown in FIG. 5B), asthese multiplexers would be coupled to enhanced group y registers 544,are also provided with signal 572.

Multiplexer MUX(n) 524 receives signal 260 (dat_algo(n)) at input 524 a.Signal 260 includes data signals provided by controller 204. MUX(n) 524receives signal 276 (actuators(n)) at input 524 b. Signal 276 representsthe status of the actuator signals present at output 530 d of enhancedgroup x registers 530. MUX(n) 524 receives signal 576 at input 524 c.Signal 576 includes a filter signal associated with each of the actuatorsignals included in signal 276. Based on the status of each of thefilter signals provided in signal 576, MUX(n) 524 will provide at output524 d either a status associated with a particular signal line providedin signal 260 from controller 204, or a status associated with aparticular signal line provided by signal 276 from enhanced group xregisters 530. MUX(n) 524 determines which signal is to be provided atoutput 524 d on signal line by signal line basis, wherein thedetermination as to which signal to provide at output 524 d for any onesignal line is individually determined based on the status of theassociated filter signal line received as signal 576 at input 524 c.

By way of example, in an embodiment where enhanced group x registers 530includes eight actuator lines represented as lines <7:0>, signal 276would include eight signals lines, one for each of lines <7:0>. Signal576 would also include eight lines, one line in signal 576 associatedwith each of the eight actuator lines in signal 276, that is, one lineassociated with each of lines <7:0>. Signal 260 would include eight datalines provided by controller 204. MUX(n) 524 is capable of providingeither the signal 260 or the signal 276 at output 524 d on a individualsignal line by signal line basis depending on the status of the inputsignals received at input 524 c. For example, based on the status of thesignal line provided in signal 576 and associated with the first signalline in signal 276, MUX(n) 524 will provide either the data lineassociated with the first data line in signal 260, or the signalassociated with the first signal line from signal 276, as a first dataline signal included in signal 578 (filtered data) at output 524 d.MUX(n) 524 will provide, on an individual data line by data line basis,either the data line from the controller 204, or a signal line fromsignal 276, at output 524 d for each of the data lines, based the statusof each the signal lines provided to MUX(n) 524 at input 524 c. Thestatus of each signal line included in signal 578 at output 524 d willbe determined by the status of the associated signal line provided atinput 524 c as provided in signal 576 (filt x (n)).

As described above, MUX(n) 524 provides signal 578 at output 524 d.However, signal 578 is not limited to any particular type of signal.Further, MUX(n) 524 is not limited to any particular type ofmultiplexer. Any type of multiplexer may be used that is capable ofproviding the signals as described above.

In register architecture 500, signal 578 is provided to MUX(n) 222 atinput 222 b. Depending on the status of the signal received by MUX(n)222 at input 222 c, either the signals received at input 222 b fromMUX(n) 524, or the signals received from external signal 254 (DQ(n))will be provided by MUX(n) 222 to enhanced group x registers 530 andmemory devices 236(1) through 236(n) as signal 574 (dat(n)).

The status of signal 572, controlling both MUX(n) 220 and MUX(n) 222, isdetermined by the status of signal 270 (reg_acc) and signal 570(filt_acc). Both of these signals are provided by CUI 508, whichcontrols the level provided by these signals as will be furtherdescribed below.

Enhanced group x registers 530 includes decoder 232. DEC 232 providessignal 290 at output 232 b to input 234 a of logic circuit 234, and to ainput 538 a of logic circuit 538. Logic circuits 234 and 538 are notlimited to any particular type of logic circuits. In variousembodiments, logic circuits 234 and 538 are AND logic circuits. Logiccircuit 234 receives signal 266 at input 234 b, and provides signal 292(enr x) at output 234 c to memory devices 236(1) through 236(n). Logiccircuit 538 receives signal 290 (enable) at input 538 a from the decoder232. Logic circuit 538 receives signal 571 (wr_filt) at input 538 b fromlogic circuit 509. Logic circuit 538 provides signal 592 (enf) at output538 c. Signal 592 is not limited to any particular type of signal. Inone embodiment, signal 592 is a digital signal.

Memory device 236(1) through 236(n) receive signal 292 at inputs 236 afor each of memory devices 236(1) through 236(n), and a portion ofsignal 574 at inputs 236 b of each memory device 236(1) through 236(n).

For example, memory device 236(1) receives the 1st component of the dataprovided as the dat(n) signal 574 at input 236(1)b of memory device236(1). Each of the additional components of the dat(n) signal 574 arereceived at an input of one of the additional memory devices up to andincluding memory device 236(n). When the “enr x” signals 292 isprovided, each of the components present in the dat(n) signal 574 willbe latched into the one of the memory devices 236(1) through 236(n) towhich the dat(n) signal 574 is coupled. Signal 574 is provided by theoutput 222 d of MUX(n) 222.

Memory devices 236(1) through 236(n) provide actuator signal 276 byproviding a signals at each output 236 c from each of memory devices236(1) through 236(n).

Memory devices 540(1) through 540(n) receive signal 592 at inputs 540 afor each of memory devices 540(1) through 540(n), and a portion ofsignal 574 at inputs 540 b for each of memory devices 540(1) through540(n). For example, memory device 540(1) receives the 1st component ofthe data provided as the dat(n) signal 574 at input 540(1)b of memorydevice 540(1). Each of the additional components of the dat(n) signal574 are received at an input of one of the additional memory devices upto and including memory device 540(n). When the “enf” signals 592 isprovided, each of the components present in the dat(n) signal 574 willbe latched into the one of the memory devices 540(1) through 540(n) towhich the dat(n) signal 574 is coupled. Signal 574 is provided by theoutput 222 d of MUX(n) 222.

In various embodiments, signal 574 differs from signal 274 of FIG. 2 inthat signal 574 as provided by MUX(n) 222 may include data provided asexternal data signal 254 (DQ(n)), or data provided by signal 578(filtered data) as provided by MUX(n) 524, as will be described ingreater detail below. Memory devices 540(1) through 540(n) providesignal 576 (filt(n)) at the outputs 540 c of each of memory devices540(1) through 540(n).

Memory devices 540(1) through 540(n) are not limited to any particulartype of memory device. In various embodiments, memory devices 540(1)through 540(n) are one or more flip-flop circuits. In variousembodiments, memory devices 540(1) through 540(n) are the same type ofmemory devices as memory devices 236(1) through 236(n).

FIG. 6 illustrates a schematic diagram 600 of one or more functionalblocks of register architecture 500. In various embodiments of registerarchitecture 500, latch 202, logic circuit 206, MUX(n) 220, MUX(x) 222,DEC 232, logic circuit 234, and memory devices 236(1) through 236(n)include the elements as described above with respect to FIG. 3.

In FIG. 6, DEC 232 provides signal 290 to both logic circuit 234 andlogic circuit 538. Logic circuit 538 also receives signal 571 at input538 b, signal 571 being provided by logic circuit 509 from output 509 c.

MUX(n) 524 includes inputs 524 a coupled to signal 260, input 524 bcoupled to signal 276, input 524 c coupled to signal 576, and output 524d providing signal 578. Depending on the status of each of the signallines included in signal 576, MUX(n) 524 will provide at signal 578either the signal associated with the particular signal line provided assignal 260 at input 524 a, or the signal associated with the particularsignal line provided as signal 276 at input 524 b on a signal line bysignal line basis. Signal 578 from MUX(n) 524 is coupled to input 222 bof MUX(n) 222. Thus, signal 578 represents a filtered data signalwherein one or more of the data lines may be provided by the datapresent in signal 276 when one or more filters are activated in memorydevices 540(1) through 540(n).

MUX(n) 220 and MUX(n) 222 receive at input 220 c and 222 c respectivelysignal 572. Signal 572 is provided by logic circuit 526. Logic circuit526 is not limited to any particular type of logic circuit. In variousembodiments, logic circuit 526 includes a NOR logic circuit 526 d andinverter logic circuit 526 e. In various embodiments, output 526 c iscoupled to driver 602.

In various embodiments, memory devices 540(1) through 540(n) includelogic elements 540 d, 540 e, and 540 f, and pass gates 540 g and 540 h.Memory devices 540(1) through 540(n) receive signal 592 at inputs 540 aat each memory device 540(1) through 540(n), and receive one of thesignals 574 provided on the signal lines from MUX(n) 222 at each input540 b of memory devices 540(1) through 540(n). Memory devices 540(1)through 540(n) provide the individual signals included in signal 576 ateach of the outputs 540 c of memory devices 540(1) through 540(n).Signal 576 includes one or more individual signal lines associated witheach of the signal lines included in signal 276. The signal linesincluded in signal 576 are provided to input 524 c of MUX(n) 524 anddetermine the coupling of signal 260 and signal 276 to signal 578through MUX(n) 524, as described above.

In various embodiments, signal 276 and signal 576 may include drivers604, 606, 608, and 610, as shown in FIG. 6.

In operation, register architecture 500 may operate in, but is notlimited to, a user mode or a test mode. The test mode in variousembodiments may include a register access test mode and a filter accesstest mode, or both. In various embodiments, when register architecture500 is in user mode, and the filters (for example memory devices 540(1)through 540(n) as explained below) have not been activated, enhancedgroup x registers 530, (and enhanced group y register 544 if present)are written to by the controller 204. When register architecture 500 isin test mode, enhanced group x registers 530, (and enhanced group yregisters 544 if present) are written to by a processor, such as theprocessor 102 of FIG. 1, or a tester or a programmer or some otherprogramming device, as described above. However, when registerarchitecture 500 is in user mode and one or more filters have beenactivated as described below, enhanced group x registers 530 (andenhanced group y registers 544 if present) may be written to bycontroller 204 for only the individual actuator signals included insignal 276 (and signal 282 provided by the actuator signal from enhancedgroup y registers 544 if present) for which a corresponding filter hasnot been activated. For individual actuator signals within signal 276(or actuator signals within signal 282) for which a filter has beenactivated, the status of these individual actuator signal will bemaintained at its stored status value despite the controller providingdata which would normally overwrite the individual actuator signal linestatus if the filter for these lines had not been activated.

Operation of register architecture 500 is now further described byreferring to FIGS. 5A and 5B, FIG. 7A, and FIG. 7B. In FIG. 5A, CUI 508is designed to recognize if a particular code provided on one or moreexternal signal lines, for example CLE signal 268, WE signal 252, andDQ(n) signal 254, is a user command or if it is a test mode entryrequest. In addition, CUI 508 is designed to recognize if a particularcode on these externally supplied signal lines is a request to set, andthus activate, one or more filters, as will be described in more detailbelow.

Assuming that CUI 508 has not detected any signals that indicate a testmode or that indicate a request to set filters, CUI 508 will set signal270 (reg_acc) to a particular setting representative of user mode, forexample but not limited to the setting as shown in FIG. 7A for the timeprior to time period “(a)”. In one embodiment, signal 270 (filt_acc)will be set to a level corresponding to a digital “zero.” During thistime, signal 570, the signals representing a filter setting mode, willalso be set to a particular setting representative of user mode. Withsignal 270 and signal 570 set as described above for a user mode, MUX(n)220, MUX(n) 222, and MUX(n) 524 will be arranged as follows. Sinceneither signal 270 nor signal 570 are set “high,” signal 572 from logiccircuit 526 will be at a level that will cause MUX(n) 220 to switch toinput 220 b, and provide signal 258 at output 220 d. In this mode,controller 204 will provide addresses through MUX(n) 220 to decoder 232.Signal 572 from logic circuit 526 will also be provided to MUX(n) 222,and will cause MUX(n) 222 to switch to input 222 b, and thus providesignal 578 at output 222 d. Assuming that no filters have been activatedin memory devices 540(1) through 540(n), signal 576 (filt(n)) will be ata level that will cause MUX(n) 524 to switch each of the individual datalines included in the data signals provided to MUX(n) 524 to input 524 ato output 524 d. In this mode, controller 204 will provide data, assignal 260 (data_algo(n)), to MUX(n) 524, which in turn will be providedfrom controller 204 as signal 578 at output 524 d to MUX(n) 222 at input222 b. This data signal from controller 204 will then be provided atoutput 222 d as signal 574 (dat(n)) to memory devices 236(1) through236(n). In conjunction with signal 266 (wr_reg) provided from controller204, memory devices 236(1) through 236(n) will proceed to latch the datasignals provided by controller 204 to memory devices 236(1) through236(n) as described above with respect to FIG. 5A.

Returning to FIG. 5A, signal 574 including the data from controller 204is also supplied to memory devices 540(1) through 540(n). However, thisdata will not be written into memory devices 540(1) through 540(n), evenwhen decoder 232 provides enable signal 290 and controller 204 provideswr_reg strobe signal 266, because each of the enable inputs of memorydevices 540(1) through 540(n) are coupled to logic circuit 538. Logiccircuit 538, while coupled to decoder 232, will only provide enablesignal 592 when also receiving a wr_filt strobe on signal 571. Asindicated above, signal 570 from CUI 508 remains inactive or “low”during user mode. Signal 570 is an input to logic circuit 509 andprovides the wr_filt signal 571, which controls the second input tologic circuit 538, and in turn provides the enable input to memorydevices 540(1) through (n). However, with signal 570 remaining low, nowr_filt signal 571 may be provided through logic circuit 509, and thuscontroller 204 is unable to write to or erase any data stored in memorydevices 540(1) through 540(n).

Therefore, the output of memory devices 540(1) through 540(n), i.e.signal 576, will remain unchanged while controller 204 writes andrewrites data to memory devices 236(1) through 236(n), because memorydevices 540(1) through 540(n) will not be receiving a level of signal592 that would allow the data from signal 574 to be incorporated intomemory devices 540(1) through 540(n). Thus, controller 204 is able towrite and re-write any of the register locations associated withenhanced group x registers 530 that provide actuator x signal 276, butis unable to write or erase the setting stored in memory devices 540(1)through 540(n).

In addition to the user mode, register architecture 500 may operate intest mode. CUI 508 is capable of detecting that a test mode is desiredbased on the external signals as described above. Detection of a testmode is not limited to any particular signal or sequence of signals.When CUI 508 determines that the register access test mode is desired,CUI 508 will change signal 270 to indicate a test mode. In variousembodiments, the change in signal 270 represents a register access testmode.

When CUI 508 determines that the register access test mode is desired,CUI 508 will provide a signal at output 508 d to indicate the registeraccess test mode. In an embodiment, signal 270 provided at output 508 dis a digital signal, and will change level to indicate the registeraccess test mode. When signal 270 changes levels to indicate theregister access test mode, signal 270 as provided at input 526 a oflogic circuit 526 will cause a corresponding change in signal 572provided at output 526 c of logic circuit 526. This change in signal 572will cause the following changes with regards to MUX(n) 220 and MUX(n)222. MUX(n) 220 will switch to input 220 a, and thus provide signal 256at output 220 d of MUX(n) 220. In this mode, latch 202 will provideaddresses provided on external DQ(n) signal 254 through MUX(n) 220 todecoder 232. MUX(n) 222 will switch to input 222 a, and thus providesignal 254 (DQ(n)) at output 222 d. In this mode, data signals will beprovided from an external source, such as a tester (not shown) throughsignal 254, through MUX(n) 222, and to memory devices 236(1) through236(n) as signal 574. In conjunction with signal 266 (wr_reg), theexternal signals may proceed to write the data signals provided as DQ(n)signal 254 to one or more memory devices, for example, memory devices236(1) through 236(n). Memory devices 236(1) through 236(n) will in turnsupply the status of the data stored in memory devices 236(1) through236(n) as actuator signal 276.

Again assuming that no filters have been set in memory devices 540(1)through 540(n), signal 576 (filt(n)) will be at a level that will causeMUX(n) 524 continue to couple each signal line included in signal 260 atinput 524 a to output 524 d, and thus couple any data provided bycontroller 204 as signal 260 to output 524 d. However, since output 524d is coupled to input 222 b of MUX(n) 222, and MUX(n) 222 is switched toreceive data from input 222 a, any data provided by controller 204 willnot be coupled to memory devices 236(1) through 236 (n), even when thesememory devices receive an enable signal on signal 292.

In addition, in register access test mode, no filter setting will bewritten into, and no existing filter setting present in memory devices540(1) through (n) may be altered. While any data provided on the DQ(n)signal 254 during the register access test mode would be coupled to thedata inputs of memory devices 540(1) through 540(n) through MUX(n) 222to each input 540 b of memory devices 540(1) through 540(n), no enablesignals will be provided at signal 571 to cause the data to be writteninto memory devices 540(1) through 540(n). As noted above with respectto user mode, signal 570 for CUI 508 remains inactive or “low” duringthe register access test mode, and thus a wr_filt signal 571 as providedby logic circuit 509 will also remain low. Therefore, during a testmode, an external tester, programmer, or processor may write, erase andrewrite any of the data in memory devices 236(1) through 236(n) withouthaving any effect on the filter settings stored in memory devices 540(1)through 540(n).

In addition to user mode and register access test mode, registerarchitecture 500 may operate in a filter setting mode. CUI 508 maydetermine that one or more filters are to be set for one or moreactuator signal lines included in signal 276 and associated withenhanced group x registers 530 (or in signal 282 as associated withenhanced group y registers 544). A determination that a filter settingmode is desired is not limited to any particular signal or sequence ofsignals. In one embodiment, CUI 508 determines that one or more filtersare to be set based on signals 268, 252, and 254 received at inputs 508a, 508 b, and 508 c, respectively, of CUI 508.

When CUI 508 determines that filters are to be set, CUI will changesignal 570 (filt_acc) to indicate a filter setting mode. In variousembodiments, when a filter setting mode is activated, CUI 508 may alsoset reg_acc signal 270 to an inactive or “low” state.

Because logic circuit 526 receives the filt_acc signal 570, logiccircuit 526 will again set signal 572 as described above with respect toregister access test mode, causing MUX(n) 220 to switch to input 220 ato receive addresses from the externally supplied signals, and settingMUX(n) 222 to switch to input 222 a to receive data from externalsignals DQ(n) signal 254.

In addition, the change in the level of signal 570 will be provided tologic circuit 509, at input 509 a. Logic circuit 509 also receivescombinational signal 264 (WE*ALE(bar)*CLE(bar)) at input 509 b. Whensignal 570 indicates filters are to be set, and combinational signal 264provides an enabling signal level at input 509 b, logic circuit 509 willprovide a change in the logic level of signal 571 (wr_filt). This changein the logic level of signal 571 is provided to logic circuit 538, andin conjunction with the enable signal 290 from decoder 232, will cause alevel change in signal 592 (enf). This change in signal 592 will enablememory devices 540(1) through 540(n) to accept data as provided atinputs 540 b, for each of memory devices 540(1) through 540(n), and toincorporate the data as stored into memory devices 540(1) through 540(n)at the outputs of memory devices 540(1) through 540(n) as signal 576.

Thus, in filter setting mode, signal 576 will be set based on the dataprovided by signal 574 and stored into memory devices 540(1) through540(n), the data as is provided by signal 574 (dat(n)) at the inputs 540b at the time this data is provided in conjunction with the write filterenable signal 571. At this time, the data supplied as signal 574corresponds to signal 254 (DQ(n)) being provided through MUX(n) 222 assignal 574. Thus, memory devices 540(1) through 540(n) will be set tothe level of signal 254 whenever the signal 571 (wr_filt) is active inconjunction with signal 290 provided by decoder 232. Thus, in filtermode, external signals may be used to write data to memory devices540(1) through 540(n). The status of the data stored in memory device540 is provided by memory devices 540(1) through (n) at output 540 c assignal 576. Signal 576 is received at input 524 c of MUX(n) 524, andwill cause MUX(n) 524 to switch, on a signal line by signal line basis,either the signal at the 524 a input or the signal at the 524 b input tothe 524 d output of MUX(n) 524.

By way of example, for any signal line in actuator signal 276 for whicha filter is to be activated, a high level may be stored into the databit of the one of memory devices 540(1) through 540(n) that correspondsto the signal line of actuator signal 276. For any of the data bits sethigh, a high level signal will be provided on the line of filter signal576 at the corresponding output 540 c. Filter signal 576 controls MUX(n)524, and high signals provided by signal 576 will cause MUX(n) 524 toswitch the particular signal line associated with the high signal sothat the MUX(n) 524 couples the output at 524 d for the particularsignal line to the 524 b input, which provides the status of the currentoutputs from each of the signal lines included in actuator signal 276.

In effect, memory devices 540(1) through 540(n), which control theswitching of MUX(n) 524, has “latched” the state of one or more signallines included in signal 276 to be maintained at whatever value ispresently stored in memory devices 236(1) through (n) for each of thesignal lines for which a filter has been activated through the storageof a set of data values into memory devices 540(1) through 540(n).

After one or more filter settings are stored in memory devices 540(1)through 540(n), CUI 508 may deactivate signal 570 (filt_acc) (and ifactivated, signal 270 (reg_acc)). Deactivation of both signal 270 andsignal 570 will cause the signal provided at the output of logic circuit526 to change to a level indicative of user mode. As a result, MUX(n)220 will switch to input 220 b, again allowing controller 204 to provideaddresses to decoder 232 by providing signal 258 as the add(n) signal272 provided at output 220 d. MUX(n) 222 will switch to input 222 b,providing signal 578 as data to output 222 d as signal 574 (dat(n)).However, MUX(n) 524 is now controlled by signal 576 as set during thefilter setting mode. Therefore, MUX(n) 524 provides as a data signal theoutput signal 578 now “filtered” by coupling, on a signal line by signalline basis, signal lines from input 524 b for signal lines havingfilters activated, and signal lines from input 524 a as supplied bycontroller 204 for signal lines not having the filters activated.

As a result of this filtering of the data by MUX(n) 524, controller 204is only able to write and rewrite data to the actuator signals includedin actuator signal 276 for which filters have not been activated. Forany signal lines included in actuator signal 276 for which a filter hasbeen set, even after returning to user mode, the output value associatedwith each of these actuator signal 276 lines is maintained at whatevervalue was present on the lines when the filter for that line was lastactivated in the filter setting mode.

FIG. 7A shows a timing diagram 700 of signals for a write operation forregister architecture 500 in user mode, wherein no filters have beenactivated. During the entire time period, reg_acc signal 270 andfilt_acc signal 570 remain low, indicating that the registerarchitecture is in user mode. During the time period designated as timesurrounding “(a)” in FIG. 7A, controller 204 provides an addresses assignal 258 (e.g., add_algo(n)) in FIG. 5A) that includes an address 701that corresponds to enhanced group x registers 530. The address isrepresented as “regx” in FIG. 7A. Since reg_acc signal 270 is low, thisaddress data will travel along a path including MUX(n) 220 to decoder232 as described above with respect to FIG. 5A. Decoder 232 will decodethe address signal, and because the address 701 corresponds to theenhanced group x registers 530, decoder 232 will provide an “en” signalas signal 290.

During this same time period, controller 204 will provide data 702 onsignal 260 (e.g., dat_algo(n) in FIG. 5A). The signal 260 includes oneor more data bits to be written to enhanced group x registers 530. Thedata is represented as “datx” in FIG. 7A. Since both the reg_acc signal270 and the filt_acc signal 570 are low, this data will travel along apath through MUX(n) 524 and MUX(n) 222, and be provided as dat(n) signal574 at inputs 236 b of each of memory devices 236(1) through 236(n).When provided with the wr_reg signal 266, the enr 292 signal willactivate, and all of the data provided by controller 204 will be writteninto memory devices 236(1) through 236(n). This is represented by theinflection point 703 in signal 276.

A similar process is show in FIG. 7A relating to controller 204 writingdata to enhanced group y registers 544 in user mode. During the timeperiod surrounding the time designated as “(b)” in FIG. 7A, controller204 provided address 704, shown as “regy” and relating to the address ofenhanced group y registers 544. During this time period, controller 204also provides data 705, shown as “daty” and relating to data to bewritten to enhanced group y registers 544. The wr_reg signal 266 isprovided to logic circuitry (not shown but included as part of enhancedgroup y registers 544) to produce enr signal 792, causing the dataprovided by controller 204 as data 705 to be written to the memorydevice or devices included in the enhanced group y registers 544. Thisis represented by the inflection point 706 in signal 282.

Because no filters have been set in the time frames represented by “(a)”and “(b)” of FIG. 7A, one or more algorithms may be executed bycontroller 204 that cause controller 204 to write and re-write any oneof the data bits as represented by “datx” and “daty” to any of enhancedgroup x registers 530 or enhanced group y registers 544 respectively.

FIG. 7B illustrates waveforms 750 representing how application of afilter to one or more actuator signal lines prevents the controller fromoverwriting the setting of the actuator signal lines in a subsequentuser mode. FIG. 7B illustrates first setting the value of the actuatorsignals in a register access test mode, then setting a filter for theactuator signal lines in a filter setting test mode, and finallyretaining the settings of the actuator signals for which filters havebeen set while operating in a user mode, as further described below.

In FIG. 7B around time period “(a)” the combination of the CLE signal268, the WE signal 252, and the DQ(n) signal 254, indicate that arequest to enter the register access test mode is being made. Inresponse, signal 270 (reg_acc) changes state to indicate that theregister access test mode exists. Time periods “(b)” and “(c)” and “(d)”represent respectively addressing a register (for example a register“51” as shown by signal 254), writing data to the register (for examplehexadecimal data 02, represented as binary 0000 0010), and exiting theregister access test mode. In various embodiments, example register 51is enhanced group x registers 530 or enhanced group y registers 544. Asshown for the time period surrounding time period “(c)” writing data toregister 51 includes a strobe signal occurring on signal 292 and setsactuator 51, bit 1 high, and sets actuator 51, bit 4 low, as shown inFIG. 7B by signals 760 and 762 respectively.

In various embodiments, time period “(e)” represents a request to entera filter setting mode. For example, based on CLE signal 268, WE signal252, and DQ(n) signal 254, CUI 508 determines that a filter setting modeis being requested. No particular signals are required to indicate afilter setting mode is being requested. Once CUI 508 determines that afilter setting mode is desired, the level of signal 570, the filt_accsignal, is changed from low to high, indicating that a filter settingmode has been entered. In addition, CUI 508 will set signal 270, thereg_acc signal, to a low state.

Time periods “(f),” “(g),” and “(h)” represent respectively addressing afilter register (for example a filter register associated with register“51” as shown by signal 254) and writing data to the filter register(for example hexadecimal data 02, represented as binary 0000 0010), andexiting the filter setting mode. The filter register is the filterregister including a data bit associated with each of the actuatorsignal lines controlled by the data stored in register 51. “Associatedwith” refers to the a memory device in the filter register storing a bitor a status that indicates whether a filter has been activated for oneparticular memory device providing at least one signal line of anactuator signal output. In various embodiments, the filter register ismemory devices 540(1) through 540(n) included in enhanced group xregisters 530. In various embodiments, there is a data bit stored inmemory devices 540(1) through 540(n) associated with each one of thememory devices included in memory devices 236(1) through 236 (n).

During time period (f), the address data on signal 254 represents thesame address, specifically “51” as addressed in the previous registeraccess test mode. However, since the filt_acc signal 570 is now highwhen data is provided during the time period “(g)” a strobe on the WEsignal 252 (WE) causes a corresponding strobe on the enf signal 592,allowing the data provided on signal 254 to be written to the filterregister 51 rather than the 51 register used to provide the actuatorsignals. As shown in FIG. 7B, example hexadecimal data 02, representedas binary 0000 0010, is written to the filter register. This filtersetting sets a filter for the actuator signal associated with the bit“1” as shown by signal 761 changing state from low to high level, whilenot activating a filter for the remaining seven bits associated with thezero values stored in the filter register.

After exiting the filter setting mode, and at time period “(i)” in FIG.7B, it is determined that a user mode is to be entered. During this timeperiod, reg_acc signal 270 and filt_acc signal 570 remain low. As notedabove, in a user mode the controller 204 will attempt to write andre-write the data stored in the registers providing the actuatorsignals, for example register 51. By way of example, at a time periodrepresented by “(j)” in FIG. 7B, an address and data are provided thatattempt to write a data value of hexadecimal 10, represented by binary0001 0000, to register 51. As shown by waveform 762, writing ahexadecimal value of 10 to register 51 causes bit 4 of register 51 tochange from a low to a high level. However, while the data representedby a hexadecimal value of 10 would normally reset the bit 1 to a valueof zero, because a filter has been set in the previous filter mode forthis particular bit, the value of bit 1 of register 51 is not reset to azero, and remains at a value of 1, as shown by signal 760 remaining highduring and after time period “(j)”.

Thus, once filters have been activated in, for example, memory devices540(1) through 540(n) of FIG. 5A, a register providing actuator signals,such as memory devices 236(1) through 236(n) in FIG. 5A, will receive a“filtered” data input signal at inputs 236 b, wherein data will besupplied by the controller 204 for data line where filters have not beenactivated, and data will be supplied from the actuator signals 276 fordata lines where filters have been activated.

Thus, by activating one or more filters by providing filter setting to afilter register such as memory devices 540(1) through 540(n) during afilter setting mode, filtered data, such as provided in signals 578, maybe applied to memory device such as memory devices 236(1) through236(n), and thus maintain one or more setting applied during a non-usermode, such as the register access test mode, when subsequently returningto a user mode. The various embodiments described achieve this in a waythat is completely transparent to the instruction and the algorithmsincluded in the controller 204, and do not require any modification tothe software or firmware included in controller 204.

FIG. 7C illustrates exemplary waveforms 790, obtained from electricalsimulations, for a register architecture, for example registerarchitecture 500, that includes enhanced group registers. FIG. 7Cillustrates exemplary waveforms 790 present at various points inregister architecture 500 over time. Exemplary waveforms 790 include ALEsignal 250, WE signal 252, DQ(n) signal 254, signal 270 (reg_acc),signal 570 (filt_acc), signal 571 (wr_filt), signal 262 (wr_algo),signal 266 (wr_reg), signal 256 (ext_add (n)), signal 258 (add_algo(n)),signal 272 (add(n)), signal 574 (dat(n)), signal 260 (dat_algo(n)),signal 290 (en), signal 292 (enr), signal 592 (enf), signal 761(filt[1]), signal 762 (actuators [4]), and signal 762 (actuator [1]).

Some embodiments include a number of methods. The activities included inthese methods may be accomplished in a number of ways, and are notnecessarily limited to a particular order or sequence for performingthese activities.

For example, FIG. 8A is a flow chart illustrating several methodsaccording to various embodiments. Various embodiments include a method800 comprising providing a memory device including a first plurality ofmemory devices and a second plurality of memory devices at block 802,the first plurality of memory devices to provide a plurality of actuatorsignals to a flash memory array, the second plurality of memory devicesto store a filter setting for each one of the first plurality of memorydevices, generating at least one data input at a memory controller to bewritten to the first plurality of memory devices at block 804, filteringthe at least one data input based on the filter setting for each one ofthe first plurality of memory devices to generate a filtered data inputat block 806, storing the filtered data input into the first pluralityof memory devices at block 808, and providing the plurality of actuatorsignals to the flash memory array based on the filtered data inputstored in the first plurality of memory devices at block 810.

In various embodiments, method 800 further includes providing the filtersetting for each of the first plurality of memory devices at block 812by writing a status bit into each one of the second plurality of memorydevices, the status bit to indicate whether a filter has been activatedfor a particular one of the first plurality of memory devices.

Method 800 may also further include storing a filter setting into thesecond plurality of memory devices during a filter access mode at block814.

Method 800 may also include wherein filtering the at least one datainput based on the filter setting includes for any status bit indicatingthat a filter has been activated for a particular one of the firstplurality of memory devices, providing in the filtered data input as thebit to be stored into that same particular one of the first plurality ofmemory devices a signal level corresponding to a signal level at theoutput of that same particular one of the first plurality of memorydevices.

Method 800 may also include wherein filtering the at least one datainput based on the filter setting includes for any status bit indicatingthat a filter has not been activated for a particular one of the firstplurality of memory devices, providing in the filtered data input as thebit to be stored into the particular one of the first plurality ofmemory devices a bit provided in the at least one data input that isdirected to be stored into the particular one of the first plurality ofmemory devices.

Method 800 may also include wherein filtering the at least one datainput includes providing a switching device including a first switchingdevice input, a second switching device input, and a switching deviceoutput, the switching device output to provide the generated filtereddata input.

Method 800 may also include wherein filtering the at least one datainput includes receiving at the first switching device input the datainput including a plurality individual data bits, each of the pluralityof individual data bits directed to a particular one of the firstplurality of memory devices, and for each of the particular one of thefirst plurality of memory devices for which a filter has not beenactivated, coupling the individual data bit directed to the particularone of the first plurality of memory devices to the switching deviceoutput.

Method 800 may also include wherein filtering the at least one datainput includes receiving at the second switching device input aplurality of actuator signals, the plurality of actuator signalsincluding an individual actuator signal provided by each one of thefirst plurality of memory devices, and for each one of the firstplurality of memory devices for which a filter has been activated,coupling the individual actuator signal provided by each one of thefirst plurality of memory devices to the switching device output.

Method 800 may also include wherein storing the filtered data input intothe second plurality of memory devices includes latching individual databits included in the filtered data input into a plurality of flip-flopcircuits.

In a further example, FIG. 8B is a flow chart illustrating severalmethods according to various embodiments. Various embodiments include amethod 850 comprising activating a first mode in a memory device atblock 852, writing a plurality of test data bits to a first plurality ofmemory devices while in the first mode at block 854, providing aplurality of actuator signals, including an output signal from each ofthe first plurality of memory devices, to control a flash memory arraywhile in the first mode at block 856, activating a second mode in thememory device at block 858, writing at least one filter setting to asecond plurality of memory devices while in the second mode at block860, activating a third mode in the memory device at block 862, writingone or more filtered data bits to the first plurality of memory deviceswhile in the third mode at block 864, and maintaining at least onesignal level of the actuator signals as determined in the first modewhile writing the one or more filtered data bits to the first pluralityof memory devices in the third mode at block 866.

Method 850 may also include wherein writing one or more filtered databits to the first plurality of memory devices includes determiningwhether a filter has been activated for a particular one of the firstplurality of memory devices, and including in the filtered data bits aparticular data bit to be written into the particular one of the firstplurality of memory devices based on whether the filter has been activefor the particular one of the first plurality of memory devices.

Method 850 may also include wherein writing a plurality of test datainto the first plurality of memory devices includes generating the testdata bits externally from the memory device. Method 850 may also includewherein writing the least one filter setting to the second plurality ofmemory devices includes generating the filter setting externally fromthe memory device. Method 850 may also include wherein writing one ormore filtered data bits to the first plurality of memory devicesincludes generating a plurality of data bits using a memory controllerembedded in the memory device, and filtering the generated one or moredata bits based on the filter setting.

FIG. 9 illustrates a system 900 that includes the register architectureof one or more embodiments of the present inventive subject matter.System 900 includes a register architecture, for example registerarchitecture 100 as shown in FIG. 1, including a processor 102 and amemory device 104. In system 900, memory device 104 includes one or moreenhanced registers used to control the operations of one or more memoryarrays. Processor 102 and memory device 104 may be included on a singleintegrated circuit, such as integrated circuit 901.

In various embodiments, integrated circuit 901 is included in acomputer, for example but not limited to computer 902. However, thedevice including memory device 104 is not limited to a particulardevice. Other devices including memory device 104 may include cellphones, personal digital assistants (PDA), televisions, and any otherdevices that include memory.

In various embodiments, computer 902 may include one or more inputdevices, such as keyboard 903 and mouse 904. Computer 902 may alsoinclude one or more devices for reading inputs from and providingoutputs to a magnetic media such as a floppy disk, for example usingdisk drive 905. Computer 902 may also include one or more devices forinputting and outputting data to a compact disk, for example compactdisk drive 906. Computer 902 may include one or more storage devices forstoring data, for example but not limited to hard drive unit 907.

Computer 902 may be coupled to one or more output devices, for examplebut not limited to a display 912. Computer 902 may be linked by one ormore networks, for example network 916. Network 916 is not limited toany particular type of network, and may include the Internet. Computer902 may be linked to network 916 one or more type of links, such as butnot limited to wireless link 915.

Tester 910 may be linked to computer 902. In various embodiments, tester910 is coupled to computer 902 to supply one or more external signals asdescribed above to memory device 104. In various embodiments, programmer920 is linked to computer 902. In various embodiments, programmer 920supplies one or more external signals to memory device 104 as describedabove.

It is to be understood that the above description is intended to beillustrative, and not restrictive. For example, the above-describedembodiments (and/or aspects thereof) may be used in combination witheach other. Many other embodiments will be apparent to those of skill inthe art upon reviewing the above description. The scope of the inventionshould, therefore, be determined with reference to the appended claims,along with the full scope of equivalents to which such claims areentitled. In the appended claims, the terms “including” and “in which”are used as the plain-English equivalents of the respective terms“comprising” and “wherein.” Also, in the following claims, the terms“including” and “comprising” are open-ended, that is, a system, device,article, or process that includes elements in addition to those listedafter such a term in a claim are still deemed to fall within the scopeof that claim. Moreover, in the following claims, the terms “first,”“second,” and “third,” etc. are used merely as labels, and are notintended to impose numerical requirements on their objects.

The Abstract of the Disclosure is provided to comply with 37 C.F.R. §1.72(b), requiring an abstract that will allow the reader to quicklyascertain the nature of the technical disclosure. It is submitted withthe understanding that it will not be used to interpret or limit thescope or meaning of the claims. In addition, in the foregoing DetailedDescription, various features may be grouped together to streamline thedisclosure. This method of disclosure is not to be interpreted asreflecting an intention that the claimed embodiments require morefeatures than are expressly recited in each claim. Rather, as thefollowing claims reflect, inventive subject matter may lie in less thanall features of a single disclosed embodiment. Thus the following claimsare hereby incorporated into the Detailed Description, with each claimstanding on its own as a separate embodiment.

CONCLUSION

A register architecture used to generate actuator signals forcontrolling one or more memory arrays may operate in various modes,including but not limited to a user mode wherein the registerarchitecture is controlled by a controller embedded in the memory chip,and a test mode wherein the register architecture and one or more memoryarrays are controlled by external signals. In previous architectures,settings written into the register architecture during for example atest mode were not capable of being kept during execution of asubsequent user mode. The embodiments of the present invention provide aregister architecture that allows one or more setting of actuatorsignals, set for example during a test mode, to be retained in asubsequent and different mode, for example a subsequent user mode. Thedetermination as to which particular actuator signals are to retain asetting after exiting a mode providing those settings may be done on anindividual actuator signal line by signal line basis, wherein thedetermination as to whether to retain a setting for a particularactuator signal line is completely independent of the determination asto whether to retain the setting for any other actuator signal line orlines.

1. A memory device comprising; an interface circuit coupled to receive acommand latch enable signal, a write enable signal, and an external datainput, the external data input to receive a test command signalrepresenting a test mode request and to receive a filter command signalrepresenting a filter setting mode request, the interface circuit toprovide a register access signal at a first interface circuit outputindicating a test mode on a register access signal line and to provide afilter access signal at a second interface circuit output indicating afilter setting mode on a filter access signal line; a controller toprovide one or more controller address data signals and to providecontroller register data; a first switching device including a firstinput, a second input, a first control input, and a first switchedoutput, the first switching device coupled to receive the controllerregister data at the first input, and coupled to receive an actuatorsignal at the second input, and coupled to receive a filter settingstatus signal at the first control input, the first switching deviceproviding a filtered data output signal at the first switched output,wherein for the filtered data output signal, the first switching devicecouples the filtered data output signal to either the controllerregister data signal or to the actuator signal based on a statusprovided by one of the filter setting status signal; a second switchingdevice including a third input, a fourth input, a second control input,and a second switched output, the second switching device coupled toreceive the external data input at the third input, and coupled toreceive the filtered data output signal at the fourth input, and coupledto receive a mode signal at the second control input, the mode signalcoupled to the register access signal and coupled to the filter accesssignal, the second switching device providing a plurality of output datasignal lines at the second switched output; a register including aregister enable input coupled to a register enable input signal toreceive a register enable input signal, and a register data inputcoupled to receive the output data signal, wherein the output datasignal includes data provided by the external data input during the testmode, and wherein the output data signal includes data provided by thefiltered data output signal during a time when the interface circuit isnot indicating the test mode and is not indicating the filter settingmode, and a register output providing the actuator signal; and A filterregister including a filter enable input coupled to receive a filterenable input signal, and a filter data input coupled to receive theoutput data signal, wherein the output data signal includes dataprovided by the external data input during the filter setting mode, thefilter register including a filter output providing the filter settingstatus signal.
 2. The memory device of claim 1, further including athird switching device including a fifth input, a sixth input, a thirdcontrol input, and a third switched output, the third switching devicecoupled to receive a latched address signal at the fifth input, andcoupled to receive the controller address data signals at the sixthinput, the third switching device providing an address signal at thethird switched output.
 3. The memory device of claim 2, furtherincluding a decoder including a decoder input and a decoder output, thedecoder input coupled to receive the address signal, the decoderproviding a decoder enable signal at the decoder output, wherein thedecoder enable signal provides an indication when data received on theaddress signal corresponds to an address associated with the registerand the filter.
 4. The memory device of claim 3, further including afirst logic circuit including a first logic input, a second logic input,and enable register output, the first logic circuit coupled to receivethe decoder enable signal at the first logic input, and coupled toreceive a write register signal at the second logic input, the firstlogic circuit to provide a register enable input signal coupled toprovide the register enable input signal to the register.
 5. The memorydevice of claim 4, wherein the write register signal is coupled to thecontroller through a third logic circuit, wherein the third logiccircuit only couples the controller to the first logic circuit when theinterface circuit is not providing a signal indicating a test mode andthe interface is not providing a signal indicating the filter settingmode.
 6. The memory device of claim 5, further including a second logiccircuit including a third logic input, a fourth logic input, and afilter enable output, the second logic circuit coupled to receive thedecoder enable signal at the third logic input, and coupled to receive awrite filter signal at the fourth logic input, the second logic circuitto provide a filter enable input signal coupled to provide the filterenable input signal to the filter.
 7. The memory device of claim 6,wherein the write filter signal is coupled to the interface circuitthrough a fourth logic circuit, wherein the fourth logic circuit onlycouples the interface circuit to the second logic circuit when theinterface circuit is providing a signal indicating the filter settingmode.
 8. A device comprising: an enhanced register to provide at leastone actuator signal to a memory array, the enhanced register including:a first memory device including a first enable input, a first data inputcoupled to a register data input, and a first memory device output, thefirst memory device output to couple to the memory array, and a secondmemory device including a second enable input, a second data inputcoupled to the register data input, and a second memory device output,wherein the second memory device provides a first output signal when thefirst memory device output is to be coupled to the register data input.9. The device of claim 8, wherein the first memory device and the secondmemory device are flip-flop circuits.
 10. The device of claim 8, furtherincluding a decoder including an address input and a decoder output, thedecoder output coupled to the first enable input of the first memorydevice and to the second enable input of the second memory device. 11.The device of claim 10, wherein the address input includes a pluralityof address input lines.
 12. The device of claim 10, wherein the decoderoutput includes an enable signal line to provide an enable signal whenan address associated with the first memory device and the second memorydevice is received at the address input of the decoder.
 13. The deviceof claim 10, further including a first logic circuit including a firstinput coupled to the decoder output, a second input to receive a firstwrite signal, and a first logic circuit output coupled to the firstenable input of the first memory device.
 14. The device of claim 10,wherein the first logic output provides a first memory device enablesignal to the first enable input when the first logic circuit receivesan enable signal from the decoder output and the second input receivesthe first write signal.
 15. The device of claim 10, further including asecond logic circuit including a third input coupled to the decoderoutput, a fourth input to receive a second write signal, and a secondlogic circuit output coupled to the second enable input of the secondmemory circuit.
 16. The device of claim 14, wherein the second logicoutput provides a second memory device enable signal to the secondenable input when the second logic circuit receives an enable signalfrom the decoder output and the second input receives the second writesignal.
 17. A method comprising: providing a memory device including afirst plurality of memory devices and a second plurality of memorydevices, the first plurality of memory devices to provide a plurality ofactuator signals to a flash memory array, the second plurality of memorydevices to store a filter setting for each one of the first plurality ofmemory devices; generating at least one data input at a memorycontroller to be written to the first plurality of memory devices;filtering the at least one data input based on the filter setting foreach one of the first plurality of memory devices to generate a filtereddata input; storing the filtered data input into the first plurality ofmemory devices; and providing the plurality of actuator signals to theflash memory array based on the filtered data input stored in the firstplurality of memory devices.
 18. The method of claim 17, furtherincluding: providing the filter setting for each of the first pluralityof memory devices by writing a status bit into each one of the secondplurality of memory devices, the status bit to indicate whether a filterhas been activated for a particular one of the first plurality of memorydevices.
 19. The method of claim 18, wherein filtering the at least onedata input based on the filter setting includes for any status bitindicating that a filter has been activated for a particular one of thefirst plurality of memory devices, providing in the filtered data inputas the status bit to be stored into that same particular one of thefirst plurality of memory devices a signal level corresponding to asignal level at the output of that same particular one of the firstplurality of memory devices.
 20. The method of claim 18, whereinfiltering the at least one data input based on the filter settingincludes for any status bit indicating that a filter has not beenactivated for a particular one of the first plurality of memory devices,providing in the filtered data input as the status bit to be stored intothe particular one of the first plurality of memory devices a bitprovided in the at least one data input that is directed to be storedinto the particular one of the first plurality of memory devices. 21.The method of claim 17, wherein filtering the at least one data inputincludes: providing a switching device including a first switchingdevice input, a second switching device input, and a switching deviceoutput, the switching device output to provide the generated filtereddata input.
 22. The method of claim 21, wherein filtering the at leastone data input includes: receiving at the first switching device inputthe data input including a plurality of individual data bits, each ofthe plurality of individual data bits directed to a particular one ofthe first plurality of memory devices; and for each of the particularone of the first plurality of memory devices for which a filter has notbeen activated, coupling the individual data bit directed to theparticular one of the first plurality of memory devices to the switchingdevice output.
 23. The method of claim 22, wherein filtering the atleast one data input includes: receiving at the second switching deviceinput the plurality of actuator signals, the plurality of actuatorsignals including an individual actuator signal provided by each one ofthe first plurality of memory devices; and for each one of the firstplurality of memory device for which a filter has been activated,coupling the individual actuator signal provided by each one of thefirst plurality of memory devices to the switching device output. 24.The method of claim 17, wherein storing the filtered data input into thesecond plurality of memory devices includes latching one or moreindividual data bits included in the filtered data input into aplurality of flip-flop circuits.
 25. The method of claim 17, furtherincluding: storing a filter setting into the second plurality of memorydevices during a filter access mode.
 26. A method comprising: activatinga first mode in a memory device; writing a plurality of test data bitsto a first plurality of memory devices included in the memory devicewhile in the first mode; providing a plurality of actuator signals,including an output signal from each of the first plurality of memorydevices, to control a flash memory array while in the first mode;activating a second mode in the memory device; writing at least onefilter setting to a second plurality of memory devices included in thememory device while in the second mode; activating a third mode in thememory device; writing one or more filtered data bits to the firstplurality of memory devices while in the third mode; and maintaining atleast one signal level included in the plurality of actuator signals asdetermined in the first mode while writing the one or more filtered databits to the first plurality of memory devices in the third mode.
 27. Themethod of claim 26, wherein writing one or more filtered data bits tothe first plurality of memory devices includes determining whether afilter has been activated for a particular one of the first plurality ofmemory devices, and including in the filtered data bits a particulardata bit to be written into the particular one of the first plurality ofmemory devices based on whether the filter has been active for theparticular one of the first plurality of memory devices.
 28. The methodof claim 26, wherein writing a plurality of test data into the firstplurality of memory devices includes generating the test data bitsexternally from the memory device.
 29. The method of claim 26, whereinwriting the at least one filter setting to the second plurality ofmemory devices includes generating the filter setting externally fromthe memory device.
 30. The method of claim 26, wherein writing one ormore filtered data bits to the first plurality of memory devicesincludes generating a plurality of data bits using a memory controllerembedded in the memory device, and filtering the generated one or moredata bits based on the filter setting.